The present invention relates to a light-blocking element for a covering for an architectural opening that eliminates the light gap between a first rail and a movable rail.
A typical window blind or shade has an expandable covering material which may be placed at any degree of expansion to cover any portion of the window opening in the vertical or horizontal direction, depending on how the rails are positioned. One configuration includes a movable bottom rail and a movable intermediate rail, with the expandable covering material extending between those two movable rails. In this configuration, the covering material may be retracted by moving the intermediate rail down or by raising the bottom rail up. This is called a Top Down Bottom Up configuration.
A problem in this configuration is that when the intermediate movable rail is moved all the way to the top against the fixed head rail and then released, there may be a slight gap between the intermediate movable rail and the fixed head rail. When back lighted, as in the daytime, this gap is very noticeable and objectionable. Furthermore, the intermediate movable rail may sag in the middle, causing this gap to be variable (greater in the center and less at the ends), which causes the gap to be even more objectionable. Also, the intermediate movable rail may not be perfectly aligned with the fixed head rail; it may be offset or skewed, which also creates a gap.